Network overlay is a mainstream architectural pattern of software-defined networking (SDN), and can implement decoupling between a network service and an underlying physical network device, thereby creating a flexible virtual network.
To improve reliability of packet transmission, network nodes in an overlay architecture perform packet forwarding using a multi-active gateway (which comprises multiple gateways sharing a same network address), and forwarding paths on which the gateways of the multi-active gateway are located form an equal-cost multi-path (ECMP) between the network nodes.
When a gateway of the multi-active gateway is restarted due to a fault, to ensure consistency between Address Resolution Protocol (ARP) entries, an SDN controller needs to send ARP entries on the SDN controller in batches to the faulty gateway. However, in the time-consuming ARP entry sending process, a network node in a network still selects a forwarding path on which the faulty gateway is located to forward traffic. In this case, because updating of ARP entries on the faulty gateway has not been completed, data forwarded to the faulty gateway may be lost.
In the prior art, a solution to this problem includes setting the faulty gateway not to work before the ARP entry sending is finished. However, other service functions of the faulty gateway are severely affected.